ABSTRACT
Bituminous tars (Ichthammol and Ichthyol Pale) are widely used in pharmaceutical, veterinary and cosmetic industries for their anti-microbial, anti-inflammatory and anti-pruritic effects. In contrast to coal tar, no phototoxicity of bituminous tars has been reported in man, although both Ichthammol and Ichthyol Pale exhibit UV absorption which is higher and broader for the former. The validated 3T3 NRU phototoxicity test indicated phototoxic potential of both substances. The phototoxicity test in a 3D human skin model (EpiDerm) only confirmed phototoxicity for Ichthammol. Human data on Ichthammol phototoxicity are missing. A photopatch test in human volunteers was performed in order to clarify the discrepancy between the phototoxicity found in the skin model and the absence of reported human phototoxicity. Following 4h exposure to 5% and 10% aqueous solutions of Ichthammol and Ichthyol Pale the test sites were irradiated with a UVA dose of 5 J/cm(2). Early phototoxic reaction (erythema) within 4-6h after irradiation was only elicited by Ichthammol and not by Ichthyol Pale. These data correspond well with those from the 3D skin model test and suggest the necessity to employ several test systems for final phototoxicity assessment. In addition to the results obtained in 3T3 NRU PT, further testing on 3D skin models may better reflect bioavailability of a given chemical in the skin, relevant to the situation in humans.
Subject(s)
Dermatitis, Phototoxic/etiology , Fibroblasts/drug effects , Quaternary Ammonium Compounds/toxicity , Skin/drug effects , Tars/toxicity , Adult , Aged , Animal Testing Alternatives , Animals , BALB 3T3 Cells , Cell Survival/drug effects , Dose-Response Relationship, Drug , Female , Humans , Mice , Middle Aged , Organ Culture Techniques , Patch Tests , Quaternary Ammonium Compounds/administration & dosage , Skin/pathology , Ultraviolet RaysABSTRACT
BACKGROUND AND OBJECTIVE: Knowledge of the optical parameters of the skin is important for all kinds of phototherapy. We analyzed penetration of laser light and proved different optical properties of in vitro specimens of normal skin and granular tissue from skin ulcers. STUDY DESIGN/MATERIALS AND METHODS: An He-Ne laser (lambda = 632.8 nm, output 50 mW) and a semiconductor laser (lambda = 675 nm, output 21 mW) were used. The distribution of laser radiation was detected by a CCD camera and evaluated by the image analysis software DIPS. RESULTS: Transmittance in granular tissue was about 2.5 times higher than that in normal skin. In the thickest skin sample (2 cm), approximately 0.3% of He-Ne laser and 2.1% of semiconductor laser light penetrated. CONCLUSIONS: The results demonstrate the percentage of incident light penetrating the individual skin layers in different localizations on the skin surface, which is a decisive factor for the selection of the radiation dose.
Subject(s)
Lasers , Skin/radiation effects , Absorption , Adolescent , Adult , Humans , Laser Therapy , Male , Phototherapy , Scattering, Radiation , Skin/cytology , Skin/metabolism , Skin Ulcer/pathology , Skin Ulcer/therapyABSTRACT
Phthalocyanines (ClAlPcS) present a new generation of substances for photodynamic treatment of tumors. To find optimal therapeutic doses for i.v. or local application, it is necessary to test the maximal non-toxic concentration on model systems. As a standard testing system (cellular substrate) for definition of the in vitro cytotoxicity, human lymphocytes separated from peripheral human blood and splenocytes obtained from rabbit spleen fragments were chosen. The vitality test on human peripheral lymphocytes proved that the used concentrations in the range 0.1-1.4 mg/ml did not significantly influence vitality of the cellular substrate. The test used for determination of the migration activity did not show any influence on MI in the concentration range 0.1-0.5 mg/ml. The higher concentrations tested (range 0.6-1.4 mg/ml) lead to reduction of the migration activity presented by a decrease in the migration index MI: for c = 0.6 mg/ml, MI = 0.85; for c = 1.4 mg/ml, MI = 0.45 (normal value for MI is in the range 0.9-1.1).
Subject(s)
Antibiotics, Antineoplastic/adverse effects , Cytotoxicity, Immunologic , Indoles/toxicity , Lymphocytes/drug effects , Organometallic Compounds/toxicity , Radiation-Sensitizing Agents/toxicity , Animals , Humans , In Vitro Techniques , RabbitsABSTRACT
The effect of various doses of He-Ne laser light (1-50 J/cm2) on phagocytic activity of peripheral blood leukocytes was studied under in vitro conditions. The used method employing microspherical particles on the basis of hydrophilic polymers minimized the amount of biological material and allowed a homogeneous irradiation by means of fiberoptics. The doses of 5 to 10 J/cm2 induced a significant increase in phagocytic activity.
Subject(s)
Lasers , Leukocytes/immunology , Phagocytosis/radiation effects , Adult , Dose-Response Relationship, Radiation , Female , Humans , In Vitro Techniques , Leukocytes/radiation effects , MaleABSTRACT
The present study is a report on the morphological, particularly ultrastructural findings in the newly formed epidermis of varicose ulcerations after a series of irradiations with a low energy He-Ne laser. The ultrastructural alterations are interpreted as most probably conditioned by the biostimulating effect of the radiation and they are compared with the results obtained by other investigators studying these problems and with findings in the epithelium of embryonal epidermis as well as in the epidermis exposed to ultraviolet radiation.
Subject(s)
Laser Therapy , Varicose Ulcer/radiotherapy , Epithelium/pathology , Epithelium/radiation effects , Epithelium/ultrastructure , Helium , Humans , Neon , Skin/pathology , Skin/radiation effects , Skin/ultrastructure , Varicose Ulcer/pathologyABSTRACT
The mechanism of the effect of He-Ne laser light was studied in the group of 22 healthy volunteers using the method of skin window. The imprint preparations of cell reaction from a reparative inflammation were examined 12, 24, and 48 hours after irradiation. It was concluded that single higher doses of radiation (50 J/cm2) accelerate the onset of macrophages in the inflammatory field and thus facilitate a more rapid and successful recovery of skin lesions.
Subject(s)
Lasers , Skin/radiation effects , Adolescent , Adult , Female , Humans , Male , Middle Aged , Skin/injuries , Skin/pathology , Skin Window TechniqueABSTRACT
The authors analysed the optical phase of radiation-skin interaction and proved different optical properties of in vitro specimens of normal skin and granular tissue from crural ulcers in the spectral region from 360 to 750 nm. In the visible spectral region, granular tissue showed reflectance lower by 25% on average than normal skin of comparable thickness. During measurement of penetration of He-Ne laser light with output of 50 mW, transmittance in granular tissue was higher by about 2.5 than in normal skin. In the thickest skin sample (19 mm), approximately 0.3% of incident light penetrated.
